U.S. patent application number 12/209891 was filed with the patent office on 2009-07-16 for fan and inner rotor motor thereof.
This patent application is currently assigned to DELTA ELECTRONICS, INC. Invention is credited to Yi-Ching CHIU, Kun-Fu CHUANG, Chin-Hong LEE, Shir-Harn YEH, Po-Hao YU.
Application Number | 20090180901 12/209891 |
Document ID | / |
Family ID | 40850785 |
Filed Date | 2009-07-16 |
United States Patent
Application |
20090180901 |
Kind Code |
A1 |
LEE; Chin-Hong ; et
al. |
July 16, 2009 |
FAN AND INNER ROTOR MOTOR THEREOF
Abstract
A fan includes an impeller and an inner rotor motor. The inner
rotor motor connects to the impeller and drives it to rotate. The
inner rotor motor includes a bushing, a shaft, a magnetic
conducting shell, a magnetic element and a stator. The shaft passes
through the bushing and is coupled to the impeller. The magnetic
conducting shell is coupled to the shaft and telescoped to the
bushing. The magnetic element is disposed around outside of the
magnetic conducting shell. The stator is disposed around outside of
the magnetic element.
Inventors: |
LEE; Chin-Hong; (Taoyuan
Hsien, TW) ; YU; Po-Hao; (Taoyuan Hsien, TW) ;
CHIU; Yi-Ching; (Taoyuan Hsien, TW) ; YEH;
Shir-Harn; (Taoyuan Hsien, TW) ; CHUANG; Kun-Fu;
(Taoyuan Hsien, TW) |
Correspondence
Address: |
Muncy, Geissler, Olds & Lowe, PLLC
P.O. BOX 1364
FAIRFAX
VA
22038-1364
US
|
Assignee: |
DELTA ELECTRONICS, INC
Taoyuan Hsien
TW
|
Family ID: |
40850785 |
Appl. No.: |
12/209891 |
Filed: |
September 12, 2008 |
Current U.S.
Class: |
417/353 |
Current CPC
Class: |
F04D 25/0606 20130101;
F04D 29/646 20130101; F04D 25/08 20130101 |
Class at
Publication: |
417/353 |
International
Class: |
F04B 17/03 20060101
F04B017/03 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 15, 2008 |
TW |
097101493 |
Claims
1. An inner rotor motor, comprising: a bushing; a shaft passing
through the bushing; a magnetic conducting shell coupled to the
shaft and telescoped to the bushing; a magnetic element disposed
around outside of the magnetic conducting shell; and a stator
disposed around outside of the magnetic element.
2. The inner rotor motor according to claim 1, wherein the shaft,
the magnetic conducting shell and the magnetic element constitute a
rotor.
3. The inner rotor motor according to claim 1, wherein the magnetic
conducting shell is coupled to the shaft by a fixing element.
4. The inner rotor motor according to claim 3, wherein the fixing
element comprises plastic or metal.
5. The inner rotor motor according to claim 1, wherein the bushing
comprises plastic or metal.
6. A fan, comprising: an impeller; a bushing; a shaft passing
through the bushing and coupled to the impeller; a magnetic
conducting shell coupled to the shaft and telescoped to the
bushing; a magnetic element disposed around outside of the magnetic
conducting shell; and a stator disposed around outside of the
magnetic element.
7. The fan according to claim 6, wherein the shaft, the magnetic
conducting shell and the magnetic element constitute a rotor.
8. The fan according to claim 6, wherein the impeller comprises a
hub and a plurality of blades disposed around the hub.
9. The fan according to claim 8, wherein the hub, the shaft and the
magnetic conducting shell are connected by way of integral
formation or insert molding formation to form a single piece.
10. The fan according to claim 8, wherein the magnetic conducting
shell and the shaft are connected with each other.
11. The fan according to claim 10, wherein the magnetic conducting
shell and the shaft are connected with each other and then coupled
to the hub by way of integral formation or insert molding
formation.
12. The fan according to claim 8, wherein the magnetic conducting
shell is coupled to the shaft by a fixing element.
13. The fan according to claim 12, wherein the fixing element
comprises plastic or metal.
14. The fan according to claim 12, wherein the fixing element is
coupled to the hub by insert molding.
15. The fan according to claim 6, wherein the bushing comprises
plastic or metal.
16. The fan according to claim 6, further comprising a frame,
wherein the impeller is disposed in the frame, and the fan is an
axial-flow fan or a centrifugal fan.
17. The fan according to claim 16, wherein the frame has a base
located at the center of a bottom portion of the frame, and the
bushing is disposed on the base.
18. The fan according to claim 17, wherein the bushings is
connected with the base by way of integral formation or insert
molding formation to form a single piece.
19. The fan according to claim 17, wherein the bushing and the base
are individually formed and then coupled to each other.
20. The fan according to claim 17, wherein the frame has a position
structure disposed at a circumstance of the base, and position
structure is an U-shaped structure.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Non-provisional application claims priority under 35
U.S.C. .sctn.119(a) on Patent Application No(s). 097101493, filed
in Taiwan, Republic of China on Jan. 15, 2008, the entire contents
of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a fan and a motor thereof
and, in particular, to a fan and an inner rotor motor thereof.
[0004] 2. Related Art
[0005] Nowadays, electronic products are minimized and have
powerful functions, so that the demands for heat dissipation are
increased accordingly. That is, the heat dissipation efficiency
must be increased for the electronic products. Because the fan has
the advantages of low cost and well developed, it is widely used as
a heat dissipating device.
[0006] Referring to FIG. 1, a conventional fan 1 has an impeller
11, a motor 12 and a frame 13. The motor 12 has a rotor magnet 121
and a stator 122. The rotor magnet 121 is disposed on the inner
surface of the hub 111 of the impeller 11, and the rotor magnet 121
is located around outside of the stator 122 corresponding to the
stator 122.
[0007] However, when the rotor magnet 121 is disposed around the
outside of the stator 122, the rotation radius, which is the
distance between the rotor magnet 121 and the axis 123, is long.
Thus, the rotational inertia of the rotor magnetic 121 is large.
Therefore, the conventional fan 1 requires higher initializing
voltage and needs more time to reach the rated speed.
[0008] Also, the large rotational inertia of the rotor magnet 121
causes the poor response speed of the fan 1 in different duty
cycles, so that the rotation speed of the fan 1 changes slowly.
Moreover, when the fan 1 rotates in high speed, a significant
vibration will occur. Furthermore, since the hub 111 of the
impeller 11 is configured to cover the rotor magnet 121 and the
stator 122, it definitely has sufficient dimension, which causes
the decreased area of the airflow channel so as to decreasing the
air flux of the fan 1.
SUMMARY OF THE INVENTION
[0009] In view of the foregoing, the present invention is to
provide an inner rotor motor capable of reducing the rotational
inertia of the rotor, and a fan using this inner rotor motor to
increase the area of the airflow channel.
[0010] To achieve the above, an inner rotor motor according to the
present invention includes a bushing, a shaft, a magnetic
conducting shell, a magnetic element and a stator. The shaft passes
through the bushing. The magnetic conducting shell is coupled to
the shaft and telescoped to the bushing. The magnetic element is
disposed around outside of the magnetic conducting shell. The
stator is disposed around outside of the magnetic element.
[0011] To achieve the above, the present invention also discloses a
fan including an impeller, a bushing, a shaft, a magnetic
conducting shell, a magnetic element and a stator. The shaft passes
through the bushing and is coupled to the impeller. The magnetic
conducting shell is coupled to the shaft and telescoped to the
bushing. The magnetic element is disposed around outside of the
magnetic conducting shell. The stator is disposed around outside of
the magnetic element.
[0012] As mentioned above, in the fan and inner rotor motor thereof
according to the present invention, the magnetic conducting shell
and the magnetic element of the rotor are disposed between the
shaft and the stator so as to reduce the dimension of the rotor as
well as that of the hub. As a result, the area of the airflow
channel can be increased, and thus the air flux of the fan can be
increased. In addition, the weight of the rotor with the reduced
dimension is decreased, and the heavy components, such as the
magnetic conducting shell and the magnetic element of the rotor,
are configured at the central part of the fan, so that the
rotational inertia of the rotor of the present invention can be
significantly smaller than that of the conventional inner rotor
motor. Therefore, the inner rotor motor can quickly reach the rated
speed without high initializing voltage, and it can also quickly
response various duty cycles to modify the rotation speed.
Moreover, the bushing, magnetic conducting shell and magnetic
element of the present invention can be combined in various ways.
For example, they can be fixed by insert molding for increasing the
structure intensity of the fan.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will become more fully understood from
the subsequent detailed description and accompanying drawings,
which are given by way of illustration only, and thus are not
limitative of the present invention, and wherein:
[0014] FIG. 1 is a schematic illustration showing a conventional
fan;
[0015] FIG. 2 is an exploded illustration showing a fan according
to a first embodiment of the present invention;
[0016] FIG. 3 is a cross-sectional view of the assembled fan of
FIG. 2 taken along line A-A; and
[0017] FIGS. 4 and 5 are schematic illustrations showing two fans
according to a second embodiment and a third embodiment of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention will be apparent from the following
detailed description, which proceeds with reference to the
accompanying drawings, wherein the same references relate to the
same elements.
[0019] Referring to FIG. 2, a fan 2 according to a first embodiment
of the present invention includes an impeller 21 and an inner rotor
motor. The fan 2 can be an axial-flow fan or a centrifugal fan. In
this embodiment, the fan 2 is, for example but not limited to, an
axial-flow fan. In addition, the fan 2 further includes a frame 23,
and the impeller 21 and the inner rotor motor are disposed in the
frame 23. The fan 23 has a base 231 and bushing 233. The base 231
is located at the center of the bottom portion of the frame 23. The
bushing 233 can be made of plastic or metal and the bushing 233 is
disposed on the base 231. The bushing 233 and the base 231 can be
integrally formed as a single unit by way of, for example, insert
molding. It is noted that the bushing 233 is not limited to be
coupled to the base 231 by way of integral formation or insert
molding formation. For instance, they can be individually formed
first and then be coupled to each other.
[0020] The impeller 21 has a hub 211 and a plurality of blades 212
disposed around the hub 211. The inner rotor motor is coupled to
the impeller 21 to drive the impeller 21 to rotate. The inner rotor
motor includes a rotor 222 and a stator 223. The rotor 222 has a
shaft 222a, a magnetic conducting shell 222b and a magnetic element
222c.
[0021] The shaft 222a passes through the bushing 233 and is coupled
to the impeller 21. The magnetic conducting shell 222b is coupled
to the shaft 222a and telescoped to the bushing 233. The magnetic
conducting shell 222b is coupled to the shaft 222a by a fixing
element 224. In addition, the shaft 222a and the magnetic
conducting shell 222b are coupled and fixed to the hub 211 by the
fixing element 224. The fixing element 224 can be made of plastic
or metal, and it can be coupled to the hub 211 by insert molding.
The magnetic element 222c is telescoped to the magnetic conducting
shell 222b. Therefore, when the impeller 21 rotates, the shaft
222a, the magnetic conducting shell 222b and the magnetic element
222c can rotate simultaneously.
[0022] The stator 223 is disposed around and corresponding to the
magnetic element 222c. The frame 23 has a position structure 232
disposed at the circumstance of the base 231. The position
structure 232 is, for example, an U-shaped structure to position
the stator 223.
[0023] FIG. 3 is a cross-sectional view of the assembled fan of
FIG. 2 taken along line A-A. Referring to FIG. 3, the magnetic
conducting shell 222b and the magnetic element 222c are disposed
between the shaft 222a and the stator 223, thereby reducing the
dimensions of the rotor 222 and the hub 211. As the results, the
area of the airflow channel can be increased so as to increase the
air flux of the fan 2. In addition, the weight of the rotor 222
with the reduced dimension can be decreased, and the heavy elements
such as the magnetic conducting shell 222b and the magnetic element
222c of the rotor 222 are configured at the central part of the fan
2, so that the rotational inertia of the rotor 222 of the present
invention can be significantly decreased. Therefore, the inner
rotor motor 2 can quickly reach the rated speed without high
initializing voltage, and it can also quickly response various duty
cycles to modify the rotation speed.
[0024] Because the dimensions of the hub 211 and the rotor 222 are
reduced, the dimension of the base 231 is also reduced. To ensure
that the circuit board 24 has sufficient layout area, the circuit
board 24 can extend outwardly from the position structure 232 as
shown in FIG. 2, so that the dimension of the circuit board 24 can
be increased.
[0025] FIG. 4 is a schematic illustration showing a fan 3 according
to a second embodiment of the present invention. Referring to FIG.
4, the difference between the fan 3 and the fan 2 of the first
embodiment is in that the hub 311 is coupled to the shaft 322a and
the magnetic conducting shell 322b by insert molding. Thus, the hub
311, the shaft 322a and the magnetic conducting shell 322b are
integrally formed as a single unit by way of, for example but not
limited to, insert molding. Therefore, a fixing element is not
required to fix the hub 311, the shaft 322a and the magnetic
conducting shell 322b. This can improve the structure intensity of
the fan 3 and lower the cost of the fan 3 due to the reduced
elements.
[0026] FIG. 5 is a schematic illustration showing a fan 4 according
to a third embodiment of the present invention. Referring to FIG.
5, the difference between the fan 4 and the fan 2 of the first
embodiment is in that the shaft 422a is coupled to the magnetic
conducting shell 422b first, and then the hub 411 is integrally
formed with the shaft 422a and the magnetic conducting shell 422b
as a single unit by way of, for example but not limited to, insert
molding: This also can improve the structure intensity of the fan
4.
[0027] In summary, in the fan and inner rotor motor thereof
according to the present invention, the magnetic conducting shell
and the magnetic element of the rotor are disposed between the
shaft and the stator so as to reduce the dimension of the rotor as
well as that of the hub. As a result, the area of the airflow
channel can be increased, and thus the air flux of the fan can be
increased. In addition, the weight of the rotor with the reduced
dimension is decreased, and the heavy components, such as the
magnetic conducting shell and the magnetic element of the rotor,
are configured at the central part of the fan, so that the
rotational inertia of the rotor of the present invention can be
significantly smaller than that of the conventional inner rotor
motor. Therefore, the inner rotor motor can quickly reach the rated
speed without high initializing voltage, and it can also quickly
response various duty cycles to modify the rotation speed.
Moreover, the bushing, magnetic conducting shell and magnetic
element of the present invention can be combined in various ways.
For example, they can be fixed by insert molding for increasing the
structure intensity of the fan.
[0028] Although the present invention has been described with
reference to specific embodiments, this description is not meant to
be construed in a limiting sense. Various modifications of the
disclosed embodiments, as well as alternative embodiments, will be
apparent to persons skilled in the art. It is, therefore,
contemplated that the appended claims will cover all modifications
that fall within the true scope of the present invention.
* * * * *